1. FIELD OF THE INVENTION
This invention pertains to a system which can be used to supervise the operation of, for example, a cable television transmission network. Such a network conventionally contains a plurality of spurred subnetworks, in which there exists a plurality of components such as amplifiers which must be supervised in order to detect malfunctions and thereby quickly locate the situs of a malfunction in the event that a malfunction actually occurs.
Thus, more specifically, this invention pertains to a device which will not only monitor the overall functioning of a branched data-transmission network, but will also supervise the proper functioning of individual components therein.
2. DESCRIPTION OF THE PRIOR ART
Various systems have been proposed which will supervise the operation of amplifiers within a cable television network. In one such device, disclosed in German Auslegungsschrift No. 26 55 404, each of the amplifiers which is to be monitored is equipped with a transmitter which operates at a frequency unique to the amplifier involved. These transmitters then send characteristic transmissions to a central distribution point, where the failure of an amplifier to produce an acceptable signal level can be detected and the situs of the failure identified to enable repairs to be made quickly. When a device of this type is to be used with large cable television networks, the cost is excessively high because of the large number of different frequencies which are required in order to specifically identify each individual component which is to be monitored. In the event that limitations are placed on the maximum number of characteristic frequencies utilized in order to reduce manufacturing costs, it only becomes possible to generally locate the situs of an amplifier failure within a given subnetwork, which results in increased repair costs because of the additional labor necessary to pin down the exact location of a failed component.
Finally, such a device has the disadvantage that conventional practice dictates that a failure of a component within the system trigger an alarm at the central cable television distribution station in order to alert operating personnel that a failure has indeed occurred. However, after a failure has occurred and appropriate repair crews have been dispatched, the alarm will repeated by sound until such time as the component in question has been fixed. Such a continuous alarm is superfluous and undesirable.
Thus, it would be advantageous to provide a device for remotely supervising the operation of a branched data-transmission network, such as a cable television network, which could be more inexpensively manufactured in a fashion that would allow a failure to be automatically localized while preventing repeated sounding of an alarm after a failure in the system has been detected.